Non-contact electrode piezoelectric sensor device and method for monitoring strong corrosive gas

Abstract

The invention discloses a non-contact electrode piezoelectric transducer device for monitoring a strongly-corrosive gas and a method. The non-contact electrode piezoelectric transducer device comprises a piezoelectric quartz wafer, an exciting electrode, an adsorption measurement tank, a controller and an impedance analyzer. According to the invention, a piezoelectric transducer is adopted to monitor the interaction process of the strongly-corrosive gas and a solid surface; adsorbance measurement errors caused by corrosion of a silver-film or a gold-film electrode originally sprayed onto the surface of the quartz wafer is radically eliminated; after separation of the exciting electrode from the quartz wafer, the mass loading capacity of a quartz crystal resonator is enhanced, and the mass change linearity range detected by the transducer is expanded; and superior light transmittance of quartz is restored, a circular ring metal electrode is used in a matching manner, and optical fibers are additionally mounted in the circular ring to be connected with a spectral measurement instrument, so that information of both mass and spectral changes of the quartz surface can be determined at the same time.

Description

technical field [0001] The invention relates to a non-contact electrode piezoelectric sensor device and method for monitoring strong corrosive gas. Background technique [0002] Since the German physicist Sauerbrey proposed the Quartz Crystal Microbalance (QCM) detection instrument technology in 1959, this sensor, which is highly sensitive to changes in surface quality, has been widely used in environmental monitoring, chemical and biological sensing, etc. Become a powerful tool for monitoring interfacial mass transfer phenomena. The core device of the quartz crystal microbalance is a piezoelectric quartz wafer, and its resonant frequency decreases linearly with the increase of surface mass under certain conditions. Sauerbrey deduced the relationship between the resonant frequency of QCM and the mass load, which is called the Sauerbrey equation. which is: [0003] ΔF=-2.26×10 -6 f 0 2 ×Δm / A (1) [0004] where F 0 is the fundamental frequency (Hz) of the quartz crystal...

AI Technical Summary

Problems solved by technology

Although many QCMs still use silver film to prepare the excitation electrode, the service life of this kind of sensor is short, and the stability of the silver electrode is usually reduced due to the corrosion of the silver electrode, so it is mostly used for disposable sensors.

The current electrode material of QCM used in the field of chemical and biological sensing is mostly gold film, but the gold film has weak adhesion on the quartz surface, which affects the reusability of the sensor. In order to increase the bonding between the gold film and the quartz surface The force makes it able to withstand relatively harsh experimental conditions (surface treatment in chemical biosensing, etc.), usually first vacuum-spray titanium (Ti) or chromium (Cr) transition layer on the surface of quartz crystal, and then vacuum-spray gold film electrode , the quartz crystal resonator prepared under this process condition has greatly improved the service life of QCM, and has become a standard sensor device in various QCM instruments. However, due to the complicated process and small production scale, the QCM sensor higher price

[0006] The adsorption characteristics of various thin film materials can be studied by using QCM, but the adsorbed substances should not be highly corrosive, otherwise it will cause electrode corrosion, which will interfere with the determination of the adsorption amount on the one hand, and affect the service life of the sensor on the other hand.

For example, after the corrosive gases such as iodine and hydrogen sulfide are adsorbed by the film modified on the surface of the quartz crystal, they will penetrate the film and corrode the gold or silver film plated on the crystal surface, which will easily lead to the instability of the QCM resonant frequency and the loss of the gold film. Or the corrosion of the silver film causes significant measurement errors

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